A tanned complexion is still considered to be an attractive feature. And, a tan is still presently achieved primarily by exposing the skin to ultraviolet (hereinafter referred to as "UV") radiation. However, the concern about damage to the skin, particularly skin cancer, caused by exposing the skin to UV radiation from the sun or other sources such as, for example, sun lamps, has caused an increased interest in products that can produce a "self-tan" without the use of UV radiation. As a result, compositions useful for inducing a tan without exposure to the sun have been introduced for many years. For example, U.S. Pat. No. 2,949,403 discloses that the compound dihydroxyacetone (hereinafter referred to as "DHA") can be used for this purpose; since that report, DHA has been widely employed in commercial self-tanning products.
Many variations of the basic DHA formulation have been proposed to overcome or bolster some of the inherent inadequacies experienced when used alone as the active agent in a formulation. One of the most frequent problems encountered with DHA is the tendency to impart an orange cast to the skin of some users; this is caused by a preponderance of yellow color development relative to red color development. In an attempt to compensate for this undesirable result, various dyes have been incorporated with DHA (U.S. Pat. No. 4,708,865). However, the use of dyes in combination with DHA causes the color of the tan to look unnatural, and therefore remains unsatisfactory to the consumer as a self-tanning product.
As awareness regarding the damaging effects of prolonged exposure to the sun and UV radiation increases, the importance of self-tanning products grows commensurately. An important feature of a self-tanner is its ability to produce a very natural looking tan on the skin. A tan produced naturally by exposing the skin to the sun is a deep dark tan with a somewhat bronze coloration. Accordingly, a sunless self-tanning product is desired that can produce a tan comparable to the natural tan achieved by exposing the skin to the sun. Therefore, there remains a need for self-tanning compositions which meet these criteria. The present invention now satisfies these consumer needs.